Rodríguez A V, Goldberg V, Viotti H, Ciappesoni G
Facultad de Veterinaria, Universidad de la República, Alberto Las Places 1620, CP 11600, Montevideo, Uruguay.
Instituto Nacional de Investigación Agropecuaria, INIA Las Brujas, Ruta 48 km.10, Rincón del Colorado, CP 90200, Canelones, Uruguay.
Open Vet J. 2015;5(2):90-7. Epub 2015 Jul 11.
Haemonchus contortus is a blood-sucking parasite causing the presence of faecal occult blood (FOB). The objective was to study three different FOB tests in order to have a new indicator of H. contortus infection in sheep that could be included in the genetic evaluation system as an alternative selection criterion to faecal worm egg count (FEC). A total of 29 Corriedale lambs were experimentally infected with 10.000 larvae of H. contortus. Stool samples were recorded for FEC and FOB tests (Hexagon, Hematest(®) and Multistix(®)), blood for packed cell volume (PCV), haemoglobin, white and red blood cell count (RBC), and FAMACHA(©) for scoring anaemia. At the end of the experiment lambs were slaughtered to worm burden count. Field infection was achieved in 309 Merino lambs under natural parasite challenge. FEC data were normalized through logarithmic transformation (LnFEC). Pearson correlation was estimated to examine the relationship between all traits. The three tests were able to detect the presence of FOB at day 11. FEC, PCV and RBC decreased to sub-normal values from day 18. FAMACHA(©) score 3 was considered to be indicative of anaemia. Most of the correlations were of high magnitude, with the exception of Multistix(®) test that was moderately correlated with haematological parameters, LnFEC and FEC. In field infection, most samples were negative to FOB tests and the correlations were lower than those calculated under experimental infection. In conclusion, FOB tests were able to detect haemonchosis earlier than FEC under high experimental parasite challenge. However, they were not able to detect FOB under natural mixed parasite challenge. FAMACHA(©) and PCV demonstrated to be good indicators of Haemonchosis, having moderate to high correlations with FEC.
捻转血矛线虫是一种吸血寄生虫，可导致粪便潜血（FOB）。目的是研究三种不同的FOB检测方法，以便找到一种绵羊捻转血矛线虫感染的新指标，该指标可纳入遗传评估系统，作为粪便虫卵计数（FEC）的替代选择标准。总共29只考力代羔羊被实验性感染了10000条捻转血矛线虫幼虫。记录粪便样本用于FEC和FOB检测（Hexagon、Hematest®和Multistix®），采集血液用于检测红细胞压积（PCV）、血红蛋白、白细胞和红细胞计数（RBC），并使用FAMACHA©对贫血进行评分。实验结束时，宰杀羔羊以计数虫负荷。在自然寄生虫感染的情况下，对309只美利奴羔羊实现了田间感染。FEC数据通过对数转换（LnFEC）进行标准化。估计Pearson相关性以检验所有性状之间的关系。这三种检测方法在第11天能够检测到FOB的存在。从第18天起，FEC、PCV和RBC降至低于正常的值。FAMACHA©评分为3被认为表明存在贫血。大多数相关性程度较高，但Multistix®检测与血液学参数、LnFEC和FEC的相关性为中等。在田间感染中，大多数样本的FOB检测为阴性，相关性低于实验感染情况下计算得出的结果。总之，在高实验性寄生虫感染情况下，FOB检测比FEC能够更早地检测到捻转血矛线虫病。然而，在自然混合寄生虫感染情况下，它们无法检测到FOB。FAMACHA©和PCV被证明是捻转血矛线虫病的良好指标，与FEC具有中等至高的相关性。
